Method for the production of porous slags or other smelts



June 8, 1948. M. GALLAl-HATCHARD 2,443,103

METHOD FOR THE PRODUCTION OF POROUS SLAGS OR OTHER SMELTS Filed May 9, 1944 v 2 Sheets-Sheet 1 Inventor l MARC E l. GAL-LM -HA-fcvmao www LM A ttorney June 8, 1948. M. GALLAl-HATCHARD ZHE METHOD FOR THE PRODUCTION OF POROUS SLAGS OR OTHER SMELTS Filed May 9, 1944 2 sheets-sheet 2 Inventor Marum. GAuLm- HMLHMD A tlorney Patented '.lune 8, 1948 iifME-THOD {"FQR #THE PR01).'UTY-:FI0Nr 20F PORQUS; SLAGS R QTLHER? SMELTS 'MareeljQallai-Hatehardihe am; England 'i Application May19, 1944, Serial No.::534,840

.Greatiritain J axillary 1.18.;` :1.9.43

have.; eliminated the eXtra-ordinary heavy main- A Itenancy.; costs ofthesemachines. These machines, .beinaexoosedto moltenmaterial .ata lterrloera- .ture oli/,about :L400-@11500` degrees .centigrade and :to 'Cold .piyatel and steam 4conterminated .by sulphunettedmhydrogen, aref subject to exceptional vWear and: ztear and `are .short lived.

In spite of this,.most. ..attractivecadvantage of sand-foaminaoter machirieoamina, the former methodoouldnotbe adopted furthe cheap. masspmdmtion, 5of Ioamed smelts V:and Ythe fmethod,

notwithstanding, ,the advantage intentionedy has .been abandoned-mainly forthe followingreasons:

1t ,is wellknownkthat `blast-Iurnace :slags vary Within Wide limits in regardto.their,chemical composition,.temperature and viscosity. "Iihe .deye1ee..o.f foamahility of, slags` .depender however, essentiallygion .thesethree properties. 4Blast furnacestl'e operated,topiloiiuce iron and -nots1ag, and, f thereorex the Aproduction..of `suitable. slags `istat,.beslisr Qnlytofeoondary importance. .It is .title toitliiataottmt teaming rnethodsrto be .succassini, -rrnistae capa-ble l of .adapting themselves lleaiily A,to ,the .variations in the propertiesofthe slag. yIn short, the methods `must .be controllable tea markedoesree. Suelo..adaptation .does not present .fa serious problem when machines. .are used. for .foaminarasiitis .comparatively `easy .to provide .forthe .control of .such maelanesrby ilary? ina .theeneed yof motement .of their, parts.. in .ometto reduce ...or incr-,ease .the quantity .of slag .subjected toitoaminenerunit of time. The same applies to the Water supply which is also readily ,variable withinwidelimits.where a maehine is .emR1QX.

{Tliere .hoivevenaiimit to the` variation-.of quaiity in connection with machine foaming. Toe.limit.isset.byftlie iaet,..that..the.iron .orteel components of the foaming machines can stand up tocrily aoertain amount. oifheat. eyondtbis, cracking or buckling occurs. A slag \or ...srne 1t wliohtleeasily-foernalalefwill temono. immediately on being brought.int o contactawith .fthewaierof the.f-ioamioaemachine,@piacentino thin ,een .walls whcliflose their; elowJn-a ten-...somme ..Sneh material can remanf -11l.t9L1.Qh1-With ,iron ,on steel without fcausinadamage. .Less foamable materiaL. however, (or. material which should.- be. foamed iessin. order :to produce a.;stronger and `heavier roam; will .have strong -cellwalls which will remainplastic vand yglowing for a considerable time. In these circumstances,...theyL material .will play .havoc with iron or. steel necessltatingrepairs, and involving, maintenance costs entirely out ofA keepingwvith .the value -of the foamed ,slag .as an ,industrial material.

Hence.,from.the economic point of View, ma- .chine foaming can. deal vonly withA the` lighter -YDespBfOam-S. ,As heavyfoams have. a great eld fofgusefulness. in .connection With structural lightweight concreta. the-impossibility of proilucingcat a reasonable cost these. kinds of .foam on. machines lis. a. serious. `drawback.

The ability to obtain the necessary control with vthe sand-foaming methods as proposed up to now was .completely lacking. ,Thebedof sand had to be.` well y'moistertedpreviouslyto` pouring. Due to vthe .veryhigh temperature of v the moltenlag, `the .comparatively .small/ quantityof. Amoisture ccntained `-in`,t,he. ,toppart of the sand bed was nstantly eyaporatedassoon as pouringcommenced, thereby,.producing.r a top ,flayer of perfectly dry porous `,sand Whichviaotedas, an leffective insulator forthe moisture. in,thelower layers and so prevented. additional. moisure reachingthe slag. The pouringpf; .the mol-ten slag on tothe sand bed from a ,single fixed 4position 'had .the lfurther disadvantage l,oi...proolucing a comparatively thick flayery of. elaewhieh. in.` consequence, could be roamed .onlyto asmall degree. asrthe yquantity of mQiSturecOntained inthe top part .oithe sand bed Was oompletelyinadequate .for treatment of ,the :layerqof slagthroughoutits. depth.. Inondation of the sand bed with water to an extent necessary to produce awaterleael .ontopofthe soft sand mud Apro-ved ineffective., as .it lead, to the production of granulated slag.insteaciV of` roamed. slag. The -formation .Oia .thicklayer of, ,slag ,could have been avoided by moyinetheladle whilethe slagtherein was. beineemntied. oyerthe sandbed, .thereby aiminglto prociueealayer of ,slag sufficiently thin lfor themoisture `.containedin the `toopart of the sandliedtoube adeguate. Under :these conditions, nowever,.,the area required to. obtain. a ,Sufficient output .oi v foarrled..slae Wouldrhaye been so. .excesslve. aste` beguneeonomical vfor.practicalV purposes- .'lhe .ultimate result oloperatine withthe sand ,foaminamethod,vvasthattlle foarri,produced was considerablyjheayienancl denser than, and could ynot Compete with, the, produce of controlled rrlaolflne` 4foarrrine .which, f orthe.sakev Aofe plant maintenance ,islimitedto 1theproduction, Aof )light foam. Guille-other. hand,vv .thense of the .sand foaming..method for there. production o f. a` ylight Afoarribv spreadinetheimolten slag. inathin layer would..n.ot .eonstitute..a.. competitive rnethocl for elimination of high plant maintenance costs, the

Moreover, the slag will receive the additional water where` it is requiredandjrom the correct sand foaming method failed and was abandoned.

Summing up the dilference between sandfoam-IV ing and machine foaming, it'can be said that' sand Y foaming could produce only f oamed-slags ,that are far too heavy, Whilst machine foaming can produce only the lighter types of foamed slags. l

The object of the present inventionis'so to' improve and adapt the original sand foaming method, that while retaining the same basic characteristics, it is brought under full control during the actual foaming operation and thus is capable of dealing effectively with thevarying qualities of molten slag or alternatively lproduce varying qualities in the foarned product. By the invention it is possible to 'obtain foa'med slag in a Wide range of quality.

kAccording to the invention, the control is achieved by providing the bed of sand with a suitably arranged net-work or layout of pipes through which an ample quantity of water can be supplied below the 'poured out molten's'lag under adjustable pressure Within the very short time required for the actual foaming. The pipes are buried in or arranged below the sand bed.

The pipes are provided lwith a suitable number of discharge points, preferably in the form of rjets or nozzles which are preferably ldirected upwards.` f v The design of the pipe network should provide for afairly equal pressure at each discharge point. y' Thecontrol of Athe Water discharged into the sand 4bed should preferably be situated at a point or points fro-rn which'the actual proceedings ontthe sand bed can easily lbe observed. This control-may consist of a numberof valves which should be so constructed or arranged as to enable the operator,'on one hand, to increase or decrease the pressure of the 'water supply and, on the other hand, to4 supply water to the whole or only a part or parts of the surface of the sand bed during the actual foaming operation.

vAs anv alternative to the use of a bed lcornposed of sand, there may be utilized, for special purposes, a bed made up from porous Aaggregates of larger size, say 1/25I or so lforming larger cavities which will permit the use of larger quantities of water and avoid the formation of 4mud or sludge.

Still another alternative is to construct the bed y t out of porous honeycombed concrete. Such a honeycom'bed bed with a well levelled surface can besaturated with watereven'to the extentpf producing a iilrn of water on top of the concrete. This film of water will initiate the foaming when themolten slagl is poured on the bed and A.be followed up by additional quantities of Water supplied fromV the lpipe network embedded Yin the porous rconcrete bed. Thus no granulation will take place which, as mentioned before, would l be thecase if molten slag were poured onto a soft sand bed which is over-saturated with water.

By means of the invention, the foaming of the molten slag will not depend only on the limited, and in most cases, inadequate quantity of water contained in the moist sand and which was supplied prior to the pouring operation; on the contrary, the slag will receive all the additional water that it requires to convert it intol foam of the required degree of porosity, :and thisboth during and after the actual' pouring operation'.

directionfnamely, fromfunderneath'. This latter factor is an important consideration, as the l application of water from the top on to the 'y and whilefthey slagl remains possessed of sufficient viscosity to allow a continuation of such penetration. K

By the method of the invention, not only can the necessary quantity of waterv be suppliedat `the right time, but, by reason of the provision for control, the water supply can -alsobe localised to particular sections of the f'oamingarea. y The ultimate'result 4of this `facility 'is that 'the operator is in a position to vary the quantity and the defgree of porosity of the foam inl patche'sfo'r localijties in relation to the layerjo'f lslag'a's a'whole. He is thus able to produce in'one'pouri'rng 'oper'- ation, andl at his choice, various" opJarititiesV of foam of different densities, which, when'crushed fand mixed, will give the particular blend'reiuired.

A further advantage ofthe invention'isy tliat the thickness of the'layer `of slag that'canbe pouredover' the foaming bed will' depend solely on the 'possibility of obtaining an adequate water supplyl within a short period, and that will not usually present any difficulty.' Providing ample water is'available,f10 to`20 tonsof vslag in a single ladle can be pouredv overthe foaming'bed withy one tilt of the ladle andhfloamed simultaneously in 1 to 2 minutesa time limit quite vimpossible with machine foaming. Y

Owing to the various factors mentioned'above, lthe floor area required for the mass production of the foamed slag according'to the' invention, can be reduced to one o r two sand beds of limited size which, by reason'kof the factthatA proper foaming takes place thereon, will cool quickly 'for clearing and reg-use.r

be achieved by providing one or more troughs for conveying the molten slag from the ladle to the sand bed. The trough or troughs may have branches or be' provided with a numbervof out;- lets for controlled distributional the molten slag over thesand bed, or may be movable vfor the speedy and equal distribution ,of `the molten slag as it comes from the ladle.Y A speedy and equal distribution of the molten slag can "be 'also achieved by laying out the sand bed in a par,- ticular way, as by making it up inthe'rform of steps so that a cascade effect is produced when the molten slag is Vpouredthereon. Under. these conditionseach step of vthe bed willl t-akelonly a certain quantity ofmolt-en slag, the overflow being passed on automatically.' to the 'nextgsltep and so on. Q y

Various arrangements for carryingwoutjthe method of the invention areV diagramiriatically illustrated,- in the accompanyingjdrawingsfin which: t l Figure 1 isa plan viewdepicting one arrange'- ment; ..7 'y

Figure 2 is a sectional elevation 4on the line 2-52 ofFigurel: a "l VFigure 3 is a plan |view illustrating amodied arrangem'entof the'water pipes; `A i Fig. 4 visa cross-sectional 'view 'i1lustra'ti'ngi` 'a further modification in4 which the. foaming bed is composed of porous ,SQlQrete;

Figure 5 is an end View, partly in section, illustrating means for distributing the slag over the foaming bed;

Figure 6 is a sectional view illustrating a suitable construction of Water jet.

Referring more particularly to Figures 1 and 2, the foaming bed is indicated at 8. It may consist of sand, or of porous aggregates of larger size than sand particles, or of porous honeycombed concrete. The bed is confined in an opentopped frame or box 9 of suitable material and of convenient size and shape, the frame or box being shown in the drawings as of rectangular shape when viewed from above.

Buried in the foaming bed are a plurality of evenly distributed jets I each of which is fed with Water by a pipe II extending from a chest or manifold I2 which is provided with a plurality of control valves I3, one for each feed pipe I I. Water is supplied to the chest or manifold by supply pipes I4 extending from storage tanks I5, the tanks holding enough water for a complete foaming operation. It Will be understood, of course, that the chest or manifold may be supplied with Water direct from the mains instead of from storage tanks.

Molten slag is supplied to the surface of the foaming bed 8 from a ladle I6 which is mounted on a Wheeled carriage I'I running on track rails I8 at the side of the foaming bed. The slag may be poured from the ladle I6 on to the foaming bed by a tilting of the ladle on its carriage or by bringing it over the foaming bed and then tilting it by means of lifting and tilting tackle (not shown).

The foaming bed is shown to be arranged horizontally, but it may be inclined slightly to promote the spreading of the molten slag thereover.

In Figure 2 the slag in foamed condition and ready for removal from the foaming bed is indicated at I9.

With the arrangement of feed pipes II and control valves I3 illustrated in Figures 1 and 2, the amount of water owing to each of the jets I0 can be controlled independently.

Figure 3 shows a different connection of the feed pipes to the jets IU. Here the same number of jets are used and they are positioned in the same Way as in the preceding figures. In this instance, however, the jets are divided into three groups each of which is fed by a single feed pipe II' from the chest or manifold I2, the latter being provided with three control valves I3, one for each pipe serving a group. The chest or manifold is supplied with Water in the same manner as before.

It will be appreciated that the grouping arrangement indicated in Figure 3 is given only by way of example and that a greater or lesser number of groups may be employed.

Where the foaming bed is composed of porous aggregate or honeycombed concrete, Figure 4 indicates the possibility of supplying through the jets In such a quantity of water that not only is the bed 8" completely saturated, but a film or layer 20 of water is provided and maintained on tcp of the bed 8" during the pouring of the molten material.

Figure illustrates means enabling an even distribution of the molten slag over the foaming bed to be obtained. Such means consist of a Wheeled trough 2l bridging the foaming bed 8" and running on track rails 22 arranged at the sides of the bed, the trough being provided with a plurality of outlet spouts 22a. The trough 1s supplied with molten slag through one or more spouts 23 extending from the ladle IB which is mounted on a Wheeled carriage I1 running in track rails I8 as before.

A suitable construction of water jet is il1ustrated in Figure 7. The jet consists of a throat portion 28, the lower end of which is joined to the feed pipe II and the upper end of which is provided with a flared mouth 29, the whole being set in concrete 30 which ,protects the jet and pipes from the effects of heat and from mechanical damage from tools or tackle used for removing the foamed slag from the foaming bed.

What I claim and desire to secure by Letters Patent of the United States is:

1. A method for the production of porous foamed slagr like material consisting of the steps of pouring molten slag like material into a container or pit having a bottom constructed of porous material, introducing water through the said bottom so as to have the bottom saturated with water prior to the pouring of the molten slag which on being poured forms an initially foamed carpet or layer, and then introducing additional water through the porous bottom to complete the foaming of the slag layer or carpet, and maintaining the slag in the container or pit until it is solidified.

2. The method as claimed in claim 1 wherein the amount of water introduced through the said bottom of porous material is controlled to give the `proper degree of foaming according to the desired physical characteristics of the foamed material and depending on the nature of the molten slag used.

3. The method as claimed in claim 1 wherein the amount of water initially introduced through the said bottom of porous material is such as to have no-t only the said bottom saturated with water but also to have a film of water overlying the said bottom during the pouring of the molten slag.

4. The method as claimed in claim 1 wherein y the water introduced through the said bottom of -porous material is supplied at spaced points.

5. The method as claimed in claim 4 wherein the water supply is controlled selectively at said spaced points to thereby vary the quantity and the degree or porosity of the foam in patches or localities in relation to the layer of slag as a whole.

MARCEL GALLAI-HATCI-IARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 824,340 Clark June 26, 1906 1,117,644 Donaldson Nov. 17, 1914 1,163,605 Schol Dec. 7, 1915 1,616,855 Hurst Feb. 8, 1927 1,916,954 Krause July 4, 1933 2,023,511 Brosius Dec. 10, 1935 2,212,962 Stuart et al. Aug. 27, 1940 2,286,078 Gallai-I-Iatchard June 9, 1942 FOREIGN PATENTS Number Country Date 839 Great Britain 1914 476,409 Great Britain Dec. 8, 1937 Y Certificate of Correction Patent No. 2,443,103 June 8, 1948 MARCEL GALLAI-HATCHARD It is hereby certified that error appears in the printed specification of the above numbered patent requirng'correction as follows:

In the grant, line 14, strike o-ut of SEVENTEEN yea-rs, same line, after grant insert until January 18, 1,963 in the heading to the printed specification, between lines 6 and 7, insert the followingzeczfz'on 1, Public Law: 6.90, August 8, 1946. Patent empz'nes January 18, 1.963 and that the Said Letters Patent Should be read as corrected above, so that the sanle may conform to the record of the case in the Patent Oice.

Slgned and sealed this 80th day of October, A. D. 1951.

[SEAL] THOMAS F. MURPHY,

Assistant ommz'saz'oner of Patents. 

